The invention concerns the technical domain of tribology in a lubricated environment.
More particularly, the invention concerns friction parts operating in a lubricated environment incorporating a friction modifier, such as automotive parts, for example.
It is well-known for a professional to use thin coatings such as DLC to reduce the friction of mechanical parts operating in a lubricated environment.
DLC coatings are also known to fulfill a second function, which is to protect the coatings against wear.
Still with the objective of enabling a significant reduction in friction coefficient, it has been proposed to add an additive that is a friction modifier. Such an additive is advantageously MoDTC which, in hot friction contact, reacts chemically to give rise to compounds such as MoS2, which is perfectly known by a professional to act as a solid lubricant.
Basing oneself on this state of the art, it can seem advantageous to combine the effects of DLC and MoDTC to benefit from the effect of synergy between the two of them, so as to further reduce the friction coefficient.
However, after performing tests, it appears that such a combination does not give satisfactory results. Notably, it has been observed that DLC coatings that contain hydrogen have a high rate of wear in the presence of MoDTC. When the DLC coating is not hydrogenated, the wear phenomenon is less pronounced but, in this case, the application is a complex and costly technique.